JP7271543B2 - Conductive particles with insulating particles, conductive materials and connection structures - Google Patents

Description

TECHNICAL FIELD The present invention relates to conductive particles with insulating particles, in which insulating particles are arranged on the surfaces of the conductive particles. The present invention also relates to a conductive material and a connection structure using the conductive particles with insulating particles.

Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin. Also, as the conductive particles, conductive particles obtained by subjecting the surface of the conductive layer to insulation treatment may be used.

The anisotropic conductive material is used to obtain various connection structures. Examples of the connection using the anisotropic conductive material include connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), Examples include connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)) and connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).

In addition, as the conductive particles, conductive particles with insulating particles in which insulating particles are arranged on the surfaces of the conductive particles may be used. Furthermore, coated conductive particles having an insulating layer disposed on the surface of the conductive layer may be used.

As an example of the conductive particles with insulating particles, the following Patent Document 1 discloses conductive particles having a conductive layer on the surface and insulating particles attached to the surface of the conductive particles. Conductive particles with particles are disclosed. In the conductive particles with insulating particles, the insulating particles have hydroxyl groups directly bonded to phosphorus atoms or hydroxyl groups directly bonded to silicon atoms on the surface.

In the following Patent Document 2, a conductive particle having a conductive portion at least on the surface, and a conductive particle body with insulating particles having a plurality of insulating particles arranged on the surface of the conductive particle, and the insulating and a coating covering the surface of the main body of the conductive particles with insulating particles is disclosed. In the conductive particles with insulating particles, the coating has a first coating portion covering the conductive particles and a second coating portion covering the surfaces of the insulating particles. In the conductive particles with insulating particles, the thickness of the first coating portion is 1/2 or less of the average particle diameter of the insulating particles.

WO2011/030715A1 JP 2013-175453 A

When conducting a conductive connection using a conductive material containing conductive particles, a plurality of upper electrodes and a plurality of lower electrodes are electrically connected to form a conductive connection. The conductive particles are preferably located between the top and bottom electrodes and not between adjacent lateral electrodes. It is desirable that there is no electrical connection between adjacent lateral electrodes.

In conventional conductive particles with insulating particles, although the conductive surface is covered with insulating particles, after conductive connection between the upper and lower electrodes to be connected, laterally adjacent electrodes that should not be connected It may be difficult to suppress the electrical connection between them. In particular, when conductive particles having a relatively large particle size are used, it may be difficult to sufficiently improve the insulation reliability between adjacent lateral electrodes in the conductively connected connection structure.

In addition, in conventional conductive particles with insulating particles, insulating particles may be arranged on the surfaces of the conductive particles by using a film such as an organic compound or an inorganic oxide. When the insulating particles are placed on the surface of the conductive particles using the coating, the insulating particles may be difficult to separate from the surfaces of the conductive particles during conductive connection, and the upper and lower electrodes to be connected It may be difficult to sufficiently improve the conduction reliability of the With conventional conductive particles with insulating particles, it is difficult to effectively improve the reliability of conduction between upper and lower electrodes that should be connected and the reliability of insulation between laterally adjacent electrodes that should not be connected. There is

An object of the present invention is to provide conductive particles with insulating particles that can effectively improve conduction reliability when electrodes are electrically connected, and can effectively improve insulation reliability. to provide. Another object of the present invention is to provide a conductive material and a connection structure using the conductive particles with insulating particles.

According to a broad aspect of the present invention, conductive particles having at least a conductive portion on the surface thereof, and a plurality of insulating particles arranged on the surfaces of the conductive particles, the insulating particles having a particle diameter of Provided is a conductive particle with insulating particles having a particle size of 500 nm or more and 1500 nm or less and a storage elastic modulus of the insulating particles at 60° C. of 100 MPa or more and 1000 MPa or less.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the conductive particles have projections on the outer surface of the conductive portion.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the ratio of the particle size of the conductive particles to the particle size of the insulating particles is 3 or more and 100 or less.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles have a swelling ratio of 1 or more and 2.5 or less.

In a specific aspect of the conductive particles with insulating particles according to the present invention, 10% or more of the total number of the insulating particles do not come into contact with other insulating particles. placed on the surface.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the conductive particles have a particle diameter of 1 μm or more and 50 μm or less.

According to a broad aspect of the present invention, there is provided a conductive material containing the conductive particles with insulating particles described above and a binder resin.

According to a broad aspect of the present invention, a first member to be connected having a first electrode on its surface, a second member to be connected having a second electrode on its surface, the first member to be connected, A connecting portion connecting the second connection target member, and the material of the connecting portion is the above-described conductive particles with insulating particles, or the conductive particles with insulating particles and a binder resin. and wherein the first electrode and the second electrode are electrically connected by the conductive portion in the conductive particles with insulating particles. .

A conductive particle with insulating particles according to the present invention comprises a conductive particle having at least a conductive portion on its surface, and a plurality of insulating particles arranged on the surface of the conductive particle. In the conductive particles with insulating particles according to the present invention, the insulating particles have a particle diameter of 500 nm or more and 1500 nm or less. In the conductive particles with insulating particles according to the present invention, the insulating particles have a storage elastic modulus at 60° C. of 100 MPa or more and 1000 MPa or less. Since the conductive particles with insulating particles according to the present invention are provided with the above configuration, the reliability of conduction can be effectively improved when the electrodes are electrically connected, and the reliability of insulation can be improved. can effectively enhance sexuality.

FIG. 1 is a cross-sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing conductive particles with insulating particles according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view showing conductive particles with insulating particles according to a third embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing a connected structure using conductive particles with insulating particles according to the first embodiment of the present invention.

The details of the present invention are described below.

(Conductive particles with insulating particles)
A conductive particle with insulating particles according to the present invention comprises a conductive particle having at least a conductive portion on its surface, and a plurality of insulating particles arranged on the surface of the conductive particle. In the conductive particles with insulating particles according to the present invention, the insulating particles have a particle diameter of 500 nm or more and 1500 nm or less. In the conductive particles with insulating particles according to the present invention, the insulating particles have a storage elastic modulus at 60° C. of 100 MPa or more and 1000 MPa or less.

Since the conductive particles with insulating particles according to the present invention are provided with the above configuration, the reliability of conduction can be effectively improved when the electrodes are electrically connected, and the reliability of insulation can be improved. can effectively enhance sexuality.

In conventional conductive particles with insulating particles, although the conductive surface is covered with insulating particles, after conductive connection between the upper and lower electrodes to be connected, laterally adjacent electrodes that should not be connected It may be difficult to suppress the electrical connection between them. In particular, when conductive particles having a relatively large particle size are used, there is a problem that the insulation reliability between adjacent lateral electrodes in the conductively connected connection structure cannot be sufficiently improved.

As a result of intensive studies aimed at solving the above problems, the present inventors have found that the above problems can be solved by using specific insulating particles. In the present invention, since specific insulating particles are used, it is possible to effectively improve the insulation reliability between adjacent lateral electrodes in the conductively connected connection structure.

In addition, in the present invention, by using specific insulating particles, the insulating particles can be effectively arranged on the surface of the conductive particles, so there is no need to use a coating such as an organic compound or an inorganic oxide. do not have. As a result, the insulating particles are easily separated from the surfaces of the conductive particles during conductive connection, and the reliability of conduction between the upper and lower electrodes to be connected can be effectively improved. According to the present invention, it is possible to effectively improve the reliability of conduction between upper and lower electrodes to be connected and the reliability of insulation between laterally adjacent electrodes that should not be connected.

In the present invention, the use of specific insulating particles greatly contributes to obtaining the above effects.

From the viewpoint of more effectively increasing the reliability of conduction and insulation between electrodes, the coefficient of variation (CV value) of the particle size of the conductive particles with insulating particles is preferably 10% or less, more preferably 5% or less.

The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ/Dn) × 100
ρ: standard deviation of particle size of conductive particles with insulating particles Dn: average value of particle size of conductive particles with insulating particles

The shape of the conductive particles with insulating particles is not particularly limited. The shape of the conductive particles with insulating particles may be spherical, may be other than spherical, or may be flat.

The above conductive particles with insulating particles are dispersed in a binder resin and suitably used to obtain a conductive material.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention.

A conductive particle 1 with insulating particles shown in FIG. The insulating particles 3 are made of an insulating material.

The conductive particles 2 have substrate particles 11 and conductive portions 12 arranged on the surfaces of the substrate particles 11 . In the conductive particles 1 with insulating particles, the conductive part 12 is a conductive layer. The conductive portion 12 covers the surface of the substrate particles 11 . The conductive particles 2 are coated particles in which the surfaces of the base particles 11 are coated with the conductive portions 12 . The conductive particles 2 have conductive portions 12 on their surfaces. In the conductive particles, the conductive portion may cover the entire surface of the substrate particle, or the conductive portion may cover a portion of the surface of the substrate particle. In the conductive particles with insulating particles, the insulating particles are preferably arranged on the surface of the conductive portion.

FIG. 2 is a cross-sectional view showing conductive particles with insulating particles according to a second embodiment of the present invention.

A conductive particle 21 with insulating particles shown in FIG. 2 includes a conductive particle 22 and a plurality of insulating particles 3 arranged on the surface of the conductive particle 22 .

The conductive particles 22 have substrate particles 11 and conductive portions 31 arranged on the surfaces of the substrate particles 11 . In the conductive particles 21 with insulating particles, the conductive portion 31 is a conductive layer. Conductive particles 22 have a plurality of core substances 32 on the surface of substrate particles 11 . The conductive portion 31 covers the substrate particles 11 and the core substance 32 . Since the core substance 32 is covered with the conductive portion 31 , the conductive particles 22 have a plurality of projections 33 on the surface. In the conductive particles 22 , the surface of the conductive portion 31 is raised by the core substance 32 to form a plurality of protrusions 33 . In the conductive particles, the conductive portion may cover the entire surface of the substrate particle, or the conductive portion may cover a portion of the surface of the substrate particle. In the conductive particles with insulating particles, the insulating particles are preferably arranged on the surface of the conductive portion.

FIG. 3 is a cross-sectional view showing conductive particles with insulating particles according to a third embodiment of the present invention.

A conductive particle 41 with insulating particles shown in FIG. 3 includes a conductive particle 42 and a plurality of insulating particles 3 arranged on the surface of the conductive particle 42 .

The conductive particles 42 have substrate particles 11 and conductive portions 51 arranged on the surfaces of the substrate particles 11 . In the conductive particles 41 with insulating particles, the conductive portion 51 is a conductive layer. The conductive particles 42 do not have a core material like the conductive particles 22 do. The conductive portion 51 has a first portion and a second portion thicker than the first portion. The conductive particles 42 have a plurality of projections 52 on their surfaces. The portion other than the plurality of protrusions 52 is the first portion of the conductive portion 51 . The plurality of protrusions 52 are the thick second portion of the conductive portion 51 . In the conductive particles, the conductive portion may cover the entire surface of the substrate particle, or the conductive portion may cover a portion of the surface of the substrate particle. In the conductive particles with insulating particles, the insulating particles are preferably arranged on the surface of the conductive portion.

Other details of the conductive particles with insulating particles will be described below.

Conductive particles:
It is preferable that the conductive particles have substrate particles and conductive portions arranged on the surfaces of the substrate particles. The conductive portion may have a single-layer structure or a multi-layer structure of two or more layers.

The particle diameter of the conductive particles is preferably 1 μm or more, more preferably 10 μm or more, and preferably 50 μm or less, more preferably 40 μm or less. When the particle diameter of the conductive particles is the lower limit or more and the upper limit or less, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrodes is sufficiently large, In addition, it becomes difficult to form agglomerated conductive particles when forming the conductive portion. Also, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portions are less likely to peel off from the surface of the substrate particles.

The particle size of the conductive particles is preferably an average particle size, more preferably a number average particle size. The particle size of the conductive particles can be determined, for example, by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating the average particle size of each conductive particle, or by laser diffraction particle size distribution measurement. is obtained by doing Regarding the conductive particles, when measuring the particle size of the conductive particles by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope, the measurement can be performed, for example, as follows.

The content of the conductive particles is added to "Technovit 4000" manufactured by Kulzer Co., Ltd. and dispersed to prepare an embedding resin for conductive particle inspection. Using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation), a cross section of the conductive particles is cut out so as to pass through the vicinity of the center of the conductive particles dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 25000, 50 conductive particles are randomly selected, and each conductive particle is observed. The circle-equivalent diameter of each conductive particle is measured as a particle diameter, and the arithmetic mean is taken as the particle diameter of the conductive particles. Instead of the conductive particle inspection embedding resin, a conductive particle inspection embedding resin with insulating particles may be produced.

The coefficient of variation (CV value) of the particle size of the conductive particles is preferably 10% or less, more preferably 5% or less. When the coefficient of variation of the particle size of the conductive particles is equal to or less than the upper limit, the reliability of electrical connection and the reliability of insulation between electrodes can be more effectively improved.

The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ/Dn) × 100
ρ: standard deviation of the particle size of the conductive particles Dn: average value of the particle size of the conductive particles

The shape of the conductive particles is not particularly limited. The conductive particles may have a spherical shape, a shape other than a spherical shape, or a flat shape.

Substrate particles:
Examples of the substrate particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The substrate particles are preferably substrate particles other than metal particles, and more preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles. The substrate particles may be substrate particles other than inorganic particles. The substrate particles may be core-shell particles comprising a core and a shell arranged on the surface of the core. The core may be an organic core and the shell may be an inorganic shell.

Various organic substances are preferably used as the material of the resin particles. Materials for the resin particles include, for example, polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, Examples include polyimide, polyamideimide, polyetheretherketone, polyethersulfone, divinylbenzene polymer, and divinylbenzene copolymer. Examples of the divinylbenzene-based copolymers include divinylbenzene-styrene copolymers and divinylbenzene-(meth)acrylate copolymers. Since the hardness of the resin particles can be easily controlled within a suitable range, the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. is preferred.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinking monomer. and crosslinkable monomers.

Examples of the non-crosslinkable monomers include styrene-based monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, Alkyl (meth)acrylate compounds such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and glycidyl (meth)acrylate Nitrile-containing monomers such as (meth)acrylonitrile; Vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, vinyl laurate, and stearic acid Acid vinyl ester compounds such as vinyl; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene, etc. and halogen-containing monomers.

Examples of the crosslinkable monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipenta Erythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate Polyfunctional (meth)acrylate compounds such as acrylate, (poly)tetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate; triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene , diallyl phthalate, diallyl acrylamide, diallyl ether, and silane-containing monomers such as γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

The term "(meth)acrylate" denotes acrylate and methacrylate. The term "(meth)acrylic" refers to acrylic and methacrylic. The term "(meth)acryloyl" refers to acryloyl and methacryloyl.

The resin particles can be obtained by polymerizing the polymerizable monomer having the ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of polymerizing by swelling a monomer together with a radical polymerization initiator using uncrosslinked seed particles.

When the substrate particles are inorganic particles excluding metal particles or organic-inorganic hybrid particles, inorganic substances for forming the substrate particles include silica, alumina, barium titanate, zirconia, carbon black, and the like. . Preferably, the inorganic substance is not a metal. The particles formed of silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed as necessary. Particles obtained by carrying out. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. It is preferred that the core is an organic core. Preferably, the shell is an inorganic shell. From the viewpoint of effectively reducing the connection resistance between electrodes, the substrate particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

Examples of the material for the organic core include the materials for the resin particles described above.

Examples of the material for the inorganic shell include the inorganic substances mentioned above as the material for the substrate particles. The inorganic shell material is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material on the surface of the core by a sol-gel method, and then firing the shell-like material. The metal alkoxide is preferably silane alkoxide. The inorganic shell is preferably made of silane alkoxide.

When the substrate particles are metal particles, examples of metals that are materials of the metal particles include silver, copper, nickel, silicon, gold, and titanium.

The particle size of the substrate particles is preferably 0.6 μm or more, more preferably 0.8 μm or more, and preferably 49.8 μm or less, more preferably 49.6 μm or less. When the particle diameter of the substrate particles is at least the lower limit and at most the upper limit, the distance between the electrodes becomes small, and small conductive particles can be obtained even if the thickness of the conductive portion (conductive layer, etc.) is increased. be done. Furthermore, it becomes difficult to aggregate when forming the conductive portion on the surface of the substrate particles, and it becomes difficult to form aggregated conductive particles.

It is particularly preferable that the particle diameter of the substrate particles is 0.9 μm or more and 49.9 μm or less. When the particle diameter of the substrate particles is in the range of 0.9 μm or more and 49.9 μm or less, aggregation becomes difficult when forming the conductive portion on the surface of the substrate particles, and aggregated conductive particles are formed. it gets harder.

The particle size of the substrate particles indicates the number average particle size. The particle size of the substrate particles is determined using a particle size distribution analyzer or the like. The particle size of the substrate particles can be determined by observing 50 arbitrary substrate particles with an electron microscope or an optical microscope, calculating the average particle size of each substrate particle, or performing laser diffraction particle size distribution measurement. It is preferable to obtain by When measuring the particle size of the conductive particles by observing 50 arbitrary base particles with an electron microscope or an optical microscope, the particle size can be measured, for example, as follows.

The content of the conductive particles is added to "Technovit 4000" manufactured by Kulzer Co., Ltd. and dispersed to prepare an embedding resin for conductive particle inspection. Using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation), a cross section of the conductive particles is cut out so as to pass through the vicinity of the center of the conductive particles dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), set the image magnification to 25000 times, randomly select 50 conductive particles, and observe the base particles of each conductive particle. do. The circle-equivalent diameter of the substrate particles in each conductive particle is measured as the particle diameter, and the arithmetic mean thereof is taken as the particle diameter of the substrate particles. Instead of the conductive particle inspection embedding resin, a conductive particle inspection embedding resin with insulating particles may be produced.

Conductive part:
In the present invention, the conductive particles have a conductive portion at least on the surface. The conductive portion preferably contains a metal. The metal forming the conductive portion is not particularly limited. Examples of the metals include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, cadmium, and alloys thereof. Alternatively, tin-doped indium oxide (ITO) may be used as the metal. Only one kind of the above metals may be used, or two or more kinds thereof may be used in combination. From the viewpoint of further lowering the connection resistance between electrodes, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is more preferable.

Moreover, from the viewpoint of effectively improving conduction reliability, it is preferable that the conductive portion and the outer surface portion of the conductive portion contain nickel. The content of nickel in 100% by weight of the conductive portion containing nickel is preferably 10% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, still more preferably 70% by weight or more, and particularly preferably is 90% by weight or more. The content of nickel in 100% by weight of the conductive portion containing nickel may be 97% by weight or more, 97.5% by weight or more, or 98% by weight or more.

Note that hydroxyl groups are often present on the surface of the conductive portion due to oxidation. In general, hydroxyl groups are present on the surface of the conductive portion made of nickel due to oxidation. Insulating particles can be arranged on the surface of the conductive portion having such hydroxyl groups (the surface of the conductive particles) through chemical bonding.

The conductive portion may be formed of one layer. The conductive portion may be formed of a plurality of layers. That is, the conductive portion may have a laminated structure of two or more layers. When the conductive portion is formed of a plurality of layers, the metal constituting the outermost layer is preferably gold, nickel, palladium, copper, or an alloy containing tin and silver, and is preferably gold. more preferred. When the metal forming the outermost layer is one of these preferred metals, the connection resistance between the electrodes is even lower. Further, when the metal forming the outermost layer is gold, the corrosion resistance is further enhanced.

The method of forming the conductive portion on the surface of the substrate particles is not particularly limited. Methods for forming the conductive portion include, for example, a method by electroless plating, a method by electroplating, a method by physical collision, a method by mechanochemical reaction, a method by physical vapor deposition or physical adsorption, and metal powder or Examples thereof include a method of coating the surface of the substrate particles with a paste containing a metal powder and a binder. The method of forming the conductive portion is preferably electroless plating, electroplating, or a method using physical collision. Methods such as vacuum deposition, ion plating, and ion sputtering can be used as the method by physical vapor deposition. Also, in the method using physical collision, for example, a sheeter composer (manufactured by Tokuju Kosakusho Co., Ltd.) or the like is used.

The thickness of the conductive portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, and preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. When the thickness of the conductive portion is equal to or more than the lower limit and equal to or less than the upper limit, sufficient conductivity is obtained, and the conductive particles are not too hard, and the conductive particles are sufficiently attached when connecting the electrodes. It can be transformed.

When the conductive portion is formed of a plurality of layers, the thickness of the conductive portion in the outermost layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, and preferably 0.5 μm or less, and more preferably. is 0.1 μm or less. When the thickness of the conductive portion of the outermost layer is equal to or more than the lower limit and equal to or less than the upper limit, the conductive portion of the outermost layer is uniform, the corrosion resistance is sufficiently high, and the connection resistance between electrodes is sufficiently low. can do.

The thickness of the conductive portion can be measured, for example, by observing the cross section of the conductive particles using a transmission electron microscope (TEM).

Core substance:
It is preferable that the conductive particles have a plurality of protrusions on the outer surface of the conductive portion. An oxide film is often formed on the surface of the electrodes connected by the conductive particles with insulating particles. In the case of using conductive particles with insulating particles having protrusions on the surface of the conductive part, by placing and crimping the conductive particles with insulating particles between the electrodes, the oxide film is effectively removed by the protrusions. can be eliminated. Therefore, the electrodes and the conductive portions are more reliably brought into contact with each other, and the connection resistance between the electrodes is further reduced. Furthermore, when the electrodes are connected, the projections of the conductive particles can effectively eliminate the insulating particles between the conductive particles and the electrodes. Therefore, the reliability of electrical connection between the electrodes is further enhanced.

As a method of forming the protrusions, a method of forming a conductive portion by electroless plating after attaching a core substance to the surface of the substrate particle, and a method of forming a conductive portion by electroless plating on the surface of the substrate particle. After that, a core substance is adhered, and then a conductive portion is formed by electroless plating. Another method of forming the projections is to form the first conductive portion on the surface of the substrate particle, then arrange the core substance on the first conductive portion, and then form the second conductive portion. and a method of adding a core substance in the middle of forming a conductive portion (first conductive portion, second conductive portion, etc.) on the surface of the substrate particle. Further, in order to form the projections, after forming the conductive portion on the base particles by electroless plating without using the core substance, plating is deposited on the surface of the conductive portion in the shape of a projection, and further electroless plating is performed. You may use the method of forming an electroconductive part by.

As a method for attaching the core substance to the surface of the substrate particles, for example, the core substance is added to the dispersion liquid of the substrate particles, and the core substance is accumulated on the surface of the substrate particles by van der Waals force. and a method of adding the core substance to a container containing the substrate particles and causing the core substance to adhere to the surfaces of the substrate particles by mechanical action such as rotation of the container. From the viewpoint of controlling the amount of the core substance to be deposited, the method of depositing the core substance on the surface of the substrate particles is preferably a method of accumulating and depositing the core substance on the surface of the substrate particles in the dispersion. preferable.

Materials constituting the core material include conductive materials and non-conductive materials. Examples of the conductive substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers. Polyacetylene etc. are mentioned as said conductive polymer. Silica, alumina, zirconia, and the like are mentioned as the non-conductive substance. From the viewpoint of further increasing the reliability of electrical connection between electrodes, the core substance is preferably a metal.

The metal is not particularly limited. Examples of the above metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead. alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and alloys composed of two or more metals such as tungsten carbide. From the viewpoint of further increasing the reliability of conduction between electrodes, the metal is preferably nickel, copper, silver or gold. The metal may be the same as or different from the metal forming the conductive portion (conductive layer).

The shape of the core substance is not particularly limited. The shape of the core substance is preferably massive. The core substance includes, for example, particulate lumps, agglomerates in which a plurality of microparticles are aggregated, irregular lumps, and the like.

The particle size (average particle size) of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the particle size of the core substance is equal to or more than the lower limit and equal to or less than the upper limit, the connection resistance between the electrodes can be effectively lowered.

The particle size of the core substance is preferably an average particle size, more preferably a number average particle size. The particle size of the core substance can be determined, for example, by observing 50 arbitrary core substances with an electron microscope or an optical microscope and calculating the average particle size of each core substance, or by performing laser diffraction particle size distribution measurement. required by In the conductive particles, when measuring the particle size of the core substance by a method of observing 50 arbitrary core substances with an electron microscope or an optical microscope, it can be measured as follows, for example.

Conductive particles are added to "Technovit 4000" manufactured by Kulzer Co., Ltd. so that the content is 30% by weight, and dispersed to prepare an embedding resin for conducting particle inspection. Using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation), a cross section of the conductive particles is cut out so as to pass through the vicinity of the center of the conductive particles dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 200,000 times, 50 conductive particles are randomly selected, and the core substance of the conductive particles is observed. The circle-equivalent diameter of the core substance in each conductive particle is measured as the particle diameter, and the arithmetic mean thereof is taken as the particle diameter of the core substance. Instead of the conductive particle inspection embedding resin, a conductive particle inspection embedding resin with insulating particles may be produced.

Insulating particles:
The conductive particles with insulating particles according to the present invention comprise a plurality of insulating particles arranged on the surface of the conductive particles. In this case, if the conductive particles with insulating particles are used for connecting the electrodes, short-circuiting between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles with insulating particles are in contact, the presence of insulating particles between the electrodes prevents short-circuiting between horizontally adjacent electrodes rather than between the upper and lower electrodes. can. When the electrodes are connected, the insulating particles between the conductive part of the conductive particles and the electrodes can be easily eliminated by pressing the conductive particles with insulating particles with two electrodes. Furthermore, in the case of the conductive particles having a plurality of protrusions on the outer surface of the conductive portion, the insulating particles between the conductive portion of the conductive particles and the electrode can be removed more easily.

In the conductive particles with insulating particles according to the present invention, the insulating particles have a particle diameter of 500 nm or more and 1500 nm or less. In the conductive particles with insulating particles according to the present invention, the insulating particles are relatively large. Therefore, even when conductive particles having a relatively large particle diameter are used, the insulation reliability between adjacent lateral electrodes in the conductively connected connection structure can be more effectively improved. .

The particle size of the insulating particles can be appropriately selected depending on the particle size of the conductive particles with insulating particles, the application of the conductive particles with insulating particles, and the like. The particle diameter of the insulating particles is preferably greater than 540 nm, more preferably 550 nm or more, still more preferably 700 nm or more, particularly preferably 800 nm or more, preferably 1500 nm or less, more preferably 1200 nm or less, and even more preferably It is less than 1000 nm, more preferably 900 nm or less, even more preferably 850 nm or less. When the particle diameter of the insulating particles satisfies the above lower limit, when the conductive particles with insulating particles are dispersed in the binder resin, the conductive portions of the conductive particles with insulating particles are in contact with each other. becomes difficult. When the particle diameter of the insulating particles satisfies the above upper limit, there is no need to increase the pressure too much to eliminate the insulating particles between the electrodes and the conductive particles when connecting the electrodes. No need to heat to high temperatures. When the particle diameter of the insulating particles satisfies the above lower limit and the above upper limit, the insulation reliability can be further effectively improved when the electrodes are electrically connected.

The particle size of the insulating particles is preferably an average particle size, more preferably a number average particle size. The particle size of the insulating particles is determined using a particle size distribution analyzer or the like. The particle diameter of the insulating particles is preferably obtained by observing 50 arbitrary insulating particles with an electron microscope or an optical microscope and calculating the average value, or by performing laser diffraction particle size distribution measurement. In the conductive particles with insulating particles, when measuring the particle size of the insulating particles by a method of observing 50 arbitrary insulating particles with an electron microscope or an optical microscope, for example, as follows. can be measured

Conductive particles with insulating particles are added to "Technovit 4000" manufactured by Kulzer Co., Ltd. so that the content is 30% by weight, and dispersed to prepare an embedding resin for conductive particle inspection. Using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation), the cross section of the conductive particles with insulating particles was cut so as to pass through the vicinity of the center of the conductive particles with insulating particles dispersed in the embedding resin for inspection. break the ice. Then, using a field emission scanning electron microscope (FE-SEM), set the image magnification to 50,000 times, randomly select 50 conductive particles with insulating particles, and conduct with each insulating particle Observe the insulating particles of the insulating particles. The circle-equivalent diameter of the insulating particles in each conductive particle with insulating particles is measured as the particle size, and the arithmetic mean of these values is taken as the particle size of the insulating particles.

The ratio of the particle size of the conductive particles to the particle size of the insulating particles (particle size of conductive particles/particle size of insulating particles) is preferably 3 or more, more preferably 6 or more, and still more preferably 16. or more, preferably 100 or less, more preferably 55 or less, and even more preferably 30 or less. When the ratio (particle diameter of conductive particles/particle diameter of insulating particles) is equal to or greater than the lower limit and equal to or lower than the upper limit, insulation reliability and conduction reliability are improved when the electrodes are electrically connected. can be enhanced more effectively.

In the conductive particles with insulating particles according to the present invention, the insulating particles have a storage elastic modulus at 60° C. of 100 MPa or more and 1000 MPa or less. The storage elastic modulus of the insulating particles at 60° C. is preferably 300 MPa or more, more preferably 500 MPa or more, and preferably 950 MPa or less, more preferably 900 MPa or less. When the storage elastic modulus of the insulating particles at 60° C. is equal to or higher than the lower limit and equal to or lower than the upper limit, the insulation reliability and conduction reliability can be more effectively improved when the electrodes are electrically connected. can be done.

The storage elastic modulus of the insulating particles at 60° C. can be measured with a dynamic viscoelasticity measuring device (“RSA3” manufactured by TA Instruments). The measurement by the dynamic viscoelasticity measuring device uses a measurement sample with a length of 10 mm, a width of 1 mm to 10 mm, and a thickness of 15 mm to 50 mm, a frequency of 10 Hz, a strain of 1%, a temperature of -10 ° C. to 210 ° C., and a heating rate. It is carried out under the condition of 5°C/min. From the measurement results, the storage elastic modulus at 60°C is calculated. The measurement sample is prepared using the same raw material (material constituting the insulating particles) as the insulating particles.

When the storage elastic modulus of the insulating particles at 60°C is 100 MPa or more and 1000 MPa or less, the insulating particles exhibit flexible properties at 60°C. When the storage elastic modulus of the insulating particles at 60°C is within the preferred range, the insulating particles exhibit very flexible properties at 60°C. Further, since the temperature at which the insulating particles are arranged on the surface of the conductive particles is about 60 ° C., when the insulating particles are arranged on the surface of the conductive particles, the insulating The particles become very flexible and can be easily placed on the surface of the conductive particles. Moreover, since the insulating particles can be easily arranged on the surfaces of the conductive particles, it is not necessary to use a coating such as an organic compound or an inorganic oxide. Therefore, the insulating particles are easily separated from the surfaces of the conductive particles during conductive connection, and the reliability of conduction between the upper and lower electrodes to be connected can be effectively improved.

Methods for adjusting the storage elastic modulus of the insulating particles at 60° C. to 100 MPa or more and 1000 MPa or less include the following methods. A method of producing insulating particles by adjusting the glass transition temperature of a monomer. A method of producing insulating particles by mixing a main monomer and a monomer having a glass transition temperature different from that of the main monomer. A method of reducing the addition ratio of the cross-linking agent to the main monomer. A method of using a cross-linking agent with a small functional number when producing insulating particles. A method using insulating particles having a porous structure. A method using insulating particles having a hollow structure. A method using insulating particles formed of an organic compound different from both ceramics and silica. Methods other than these may be used.

Moreover, from the viewpoint of making the storage elastic modulus of the insulating particles at 60° C. within the preferable range, the insulating particles are preferably obtained by polymerizing a polymerizable compound. Examples of the polymerizable compound include the materials for the resin particles described above. The side chain of the polymerizable compound is preferably long. Since the side chain of the polymerizable compound is long, it is possible to obtain insulating particles exhibiting even more flexible properties. Also, as mentioned above, the insulating particles are relatively large. In order to obtain insulating particles having a large particle size, it is preferable that the polymerizable compound has a short side chain. Although insulating particles with a large particle size can be easily obtained by polymerizing a polymerizable compound with a short side chain, insulating particles obtained from a polymerizable compound with a short side chain exhibit flexible properties. It is difficult to let Therefore, as a method for imparting flexibility to insulating particles obtained by a polymerizable compound having a short side chain, a polymerizable compound having a short side chain is added to a polymerizable compound having a short side chain without participating in the polymerization of the polymerizable compound. and a method of introducing a reactive functional group having reactivity with. By introducing the reactive functional group into a polymerizable compound with a short side chain, the polymerizable compound with a short side chain is polymerized to obtain insulating particles, and then the reactive functional group and the compound with a long chain length are combined. can impart flexibility to the insulating particles. As a result, the insulating particles can be easily arranged on the surface of the conductive particles.

The swelling ratio of the insulating particles is preferably 1 or more, more preferably 1.2 or more, and preferably 2.5 or less, more preferably 2 or less. When the swelling ratio is equal to or higher than the lower limit, the insulating particles can be arranged more easily on the surfaces of the conductive particles. When the swelling ratio is equal to or less than the upper limit, the insulation reliability and conduction reliability can be further effectively improved when the electrodes are electrically connected.

The swelling ratio is an index of the flexibility of the insulating particles. A higher swelling ratio indicates that the insulating particles are more flexible.

The swelling ratio can be measured as follows.

Using the same raw material as the insulating particles (material constituting the insulating particles), a measurement sample of 10 mm long×5 mm wide and 0.5 mm thick is prepared. The obtained measurement sample is weighed and immersed in 100 g of toluene at 25° C. for 20 hours. After that, the measurement sample is taken out, dried at 160° C. for 30 minutes, and the weight of the measurement sample after drying is measured. The swelling ratio can be calculated from the weight change of the measurement sample before and after immersion in toluene according to the following formula (1).

Swelling ratio=[Weight (g) of measurement sample after immersion in toluene/Weight (g) of measurement sample before immersion in toluene] Equation (1)

From the viewpoint of more effectively improving the insulation reliability and conduction reliability when the electrodes are electrically connected, 10% or more of the total number of the insulating particles is the other insulating particles. It is preferably arranged on the surface of the conductive particles so as not to contact the. From the viewpoint of more effectively improving the insulation reliability and conduction reliability when the electrodes are electrically connected, 30% or more of the total number of the insulating particles is the other insulating particles. It is more preferably arranged on the surface of the conductive particles so as not to come into contact with.

The ratio of the number of insulating particles that are not in contact with other insulating particles is preferably calculated by observing 20 conductive particles with insulating particles with a scanning electron microscope (SEM). Specifically, the conductive particles with insulating particles are observed from one direction with a scanning electron microscope (SEM), the number of insulating particles in each conductive particle with insulating particles, and contact with other insulating particles It is preferable to obtain by calculating the number of insulating particles that are not exposed and calculating the average value.

Examples of the material forming the insulating particles include insulating resins. Examples of the insulating resin include materials for resin particles that can be used as base particles.

Specific examples of the insulating resin that is the material of the insulating particles include polyolefin compounds, (meth)acrylate polymers, (meth)acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermal Examples include curable resins and water-soluble resins.

Examples of the polyolefin compound include polyethylene, ethylene-vinyl acetate copolymer and ethylene-acrylate copolymer. Examples of the (meth)acrylate polymer include polymethyl (meth)acrylate, polyethyl (meth)acrylate and polybutyl (meth)acrylate. Examples of the block polymer include polystyrene, styrene-acrylate copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include epoxy resin, phenol resin and melamine resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide and methyl cellulose.

When adjusting the storage modulus of the insulating particles at 60° C. with a cross-linking agent, the material constituting the insulating particles preferably contains a cross-linking agent. From the viewpoint of adjusting the storage modulus at 60° C. to 100 MPa or more and 1000 MPa or less, the cross-linking agent is preferably a bifunctional to hexafunctional cross-linking agent. The bifunctional to hexafunctional crosslinking agent is preferably a bifunctional to hexafunctional (meth)acrylate monomer, more preferably a bifunctional to tetrafunctional (meth)acrylate monomer. More preferred are functional (meth)acrylate monomers. As the bifunctional to hexafunctional (meth)acrylate monomer, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate or ethylene glycol dimethacrylate is preferable, and ethylene glycol dimethacrylate is more preferable.

From the viewpoint of easily adjusting the storage elastic modulus of the insulating particles at 60° C. to 100 MPa or more and 1000 MPa or less, a cross-linking agent is added to 100 parts by weight of the material having the highest content among the materials constituting the insulating particles. The amount is preferably 0.001 parts by weight or more, more preferably 0.01 parts by weight or more, and even more preferably 0.1 parts by weight or more. From the viewpoint of easily adjusting the storage elastic modulus of the insulating particles at 60° C. to 100 MPa or more and 1000 MPa or less, a cross-linking agent is added to 100 parts by weight of the material having the highest content among the materials constituting the insulating particles. The amount is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, and even more preferably 6 parts by weight or less.

Examples of the method for disposing the insulating particles on the surface of the conductive portion include chemical methods and physical or mechanical methods. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, an emulsion polymerization method, and the like. Examples of the physical or mechanical methods include spray drying, hybridization, electrostatic adhesion, atomization, dipping and vacuum deposition. From the viewpoint of more effectively improving the insulation reliability and conduction reliability when the electrodes are electrically connected, the method of disposing the insulating particles on the surface of the conductive portion is a physical method. Preferably.

The outer surface of the conductive portion and the outer surface of the insulating particles may each be coated with a compound having a reactive functional group. The outer surface of the conductive part and the outer surface of the insulating particles may not be directly chemically bonded, but may be indirectly chemically bonded by a compound having a reactive functional group. After introducing carboxyl groups to the outer surface of the conductive portion, the carboxyl groups may be chemically bonded to functional groups on the outer surface of the insulating particles via a polymer electrolyte such as polyethyleneimine.

In the conductive particles with insulating particles according to the present invention, two or more kinds of insulating particles having different particle sizes may be used in combination. By using two or more types of insulating particles with different particle sizes together, the insulating particles with a small particle size enter the gaps covered by the insulating particles with a large particle size, and the above coverage is more effectively achieved. can be enhanced.

The coefficient of variation (CV value) of the particle diameter of the insulating particles is preferably 20% or less. When the coefficient of variation of the particle size of the insulating particles is equal to or less than the upper limit, the thickness of the portion covered with the insulating particles of the obtained conductive particles with insulating particles becomes more uniform, and the conductive connection is achieved. A uniform pressure can be more easily applied, and the connection resistance between the electrodes can be further reduced.

The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ/Dn) × 100
ρ: standard deviation of particle size of insulating particles Dn: average value of particle size of insulating particles

The shape of the insulating particles is not particularly limited. The insulating particles may have a spherical shape, a shape other than a spherical shape, or a flat shape.

(Conductive material)
The conductive material according to the present invention contains the above-described conductive particles with insulating particles and a binder resin. The conductive particles with insulating particles are preferably dispersed in a binder resin for use, and preferably dispersed in a binder resin for use as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection between electrodes. The conductive material is preferably a conductive material for circuit connection. Since the above-described conductive particles with insulating particles are used in the conductive material, the reliability of insulation and the reliability of conduction between electrodes can be further improved.

The binder resin is not particularly limited. A known insulating resin is used as the binder resin. The binder resin preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. Examples of the curable component include photocurable components and thermosetting components. The photocurable component preferably contains a photocurable compound and a photopolymerization initiator. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent.

Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers and elastomers. Only one kind of the binder resin may be used, or two or more kinds thereof may be used in combination.

Examples of the vinyl resin include vinyl acetate resin, acrylic resin and styrene resin. Examples of the thermoplastic resins include polyolefin resins, ethylene-vinyl acetate copolymers and polyamide resins. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin and unsaturated polyester resin. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, hydrogenated products of styrene-butadiene-styrene block copolymers, and styrene-isoprene. - hydrogenated products of styrene block copolymers; Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

In addition to the conductive particles with insulating particles and the binder resin, the conductive material includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a coloring agent, an antioxidant, and a heat stabilizer. Various additives such as agents, light stabilizers, UV absorbers, lubricants, antistatic agents and flame retardants may also be included.

As a method for dispersing the conductive particles with insulating particles in the binder resin, a conventionally known dispersing method can be used, and there is no particular limitation. Examples of the method for dispersing the conductive particles with insulating particles in the binder resin include the following methods. A method of adding the conductive particles with insulating particles to the binder resin and then kneading and dispersing the mixture with a planetary mixer or the like. A method of uniformly dispersing the conductive particles with insulating particles in water or an organic solvent using a homogenizer or the like, then adding the dispersed particles to the binder resin, kneading the particles with a planetary mixer or the like to disperse them. A method of diluting the binder resin with water, an organic solvent, or the like, adding the conductive particles with insulating particles, and kneading and dispersing the mixture with a planetary mixer or the like.

The viscosity (η25) of the conductive material at 25° C. is preferably 30 Pa·s or more, more preferably 50 Pa·s or more, and preferably 400 Pa·s or less, more preferably 300 Pa·s or less. When the viscosity of the conductive material at 25 ° C. is at least the lower limit and at most the upper limit, the insulation reliability between the electrodes can be more effectively improved, and the conduction reliability between the electrodes can be more effectively improved. can be increased to The viscosity (η25) can be appropriately adjusted depending on the types and amounts of ingredients to be blended.

The viscosity (η25) can be measured at 25° C. and 5 rpm using, for example, an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.).

The conductive material according to the present invention can be used as conductive paste, conductive film, and the like. When the conductive material according to the present invention is a conductive film, a film containing no conductive particles may be laminated on a conductive film containing conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, and particularly preferably 70% by weight or more. is 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is the lower limit or more and the upper limit or less, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target members connected by the conductive material is further improved. can be done.

In 100% by weight of the conductive material, the content of the conductive particles with insulating particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and preferably 80% by weight or less. It is preferably 60% by weight or less, more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the conductive particles with insulating particles is equal to or more than the lower limit and equal to or less than the upper limit, reliability of electrical connection and reliability of insulation between electrodes can be further enhanced.

(connection structure)
A connection structure according to the present invention includes a first connection object member having a first electrode on the surface, a second connection object member having a second electrode on the surface, the first connection object member, and a connecting portion connecting the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the conductive particles with insulating particles described above, or a conductive material containing the conductive particles with insulating particles and a binder resin. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by the conductive portion in the conductive particles with insulating particles.

The connection structure comprises a step of placing the conductive particles with insulating particles or the conductive material between the first connection target member and the second connection target member, and thermocompression bonding, It can be obtained through the step of electrically connecting. It is preferable that the insulating particles are detached from the conductive particles with insulating particles during the thermocompression bonding.

FIG. 4 is a cross-sectional view schematically showing a connected structure using conductive particles with insulating particles according to the first embodiment of the present invention.

A connection structure 81 shown in FIG. 4 includes a first connection target member 82, a second connection target member 83, and a connection portion that connects the first connection target member 82 and the second connection target member 83. 84. The connecting portion 84 is made of a conductive material containing the conductive particles 1 with insulating particles. The connecting portion 84 is preferably formed by curing a conductive material containing a plurality of conductive particles 1 with insulating particles. In addition, in FIG. 4, the conductive particles 1 with insulating particles are shown schematically for convenience of illustration. In place of the conductive particles 1 with insulating particles, conductive particles 21 or 41 with insulating particles may be used.

The first connection target member 82 has a plurality of first electrodes 82a on its surface (upper surface). The second connection target member 83 has a plurality of second electrodes 83a on its surface (lower surface). The first electrode 82a and the second electrode 83a are electrically connected by the conductive particles 2 in the conductive particles 1 with one or more insulating particles. Therefore, the first connection target member 82 and the second connection target member 83 are electrically connected by the conductive portion in the conductive particles 1 with insulating particles.

The manufacturing method of the connection structure is not particularly limited. As an example of a method for manufacturing a connected structure, the conductive material is arranged between a first member to be connected and a second member to be connected to obtain a laminate, and then the laminate is heated and pressurized. methods and the like. The pressure of the thermocompression bonding is preferably 40 MPa or higher, more preferably 60 MPa or higher, and preferably 90 MPa or lower, more preferably 70 MPa or lower. The heating temperature for the thermocompression bonding is preferably 80° C. or higher, more preferably 100° C. or higher, and preferably 140° C. or lower, more preferably 120° C. or lower. When the pressure and temperature of the thermocompression bonding are the above lower limit or more and the above upper limit or less, the insulating particles can be easily detached from the surface of the conductive particles with insulating particles at the time of conductive connection, and the reliability of conduction between electrodes is improved. can be further enhanced.

When the laminate is heated and pressurized, the insulating particles present between the conductive particles and the first and second electrodes can be eliminated. For example, during the heating and pressurization, the conductive particles, the insulating particles present between the first electrode and the second electrode, the conductive particles with the insulating particles Easily detached from the surface of the particles. During the heating and pressurization, some of the insulating particles may be detached from the surface of the conductive particles with insulating particles, and the surface of the conductive portion may be partially exposed. The exposed portion of the conductive portion is in contact with the first electrode and the second electrode, thereby electrically connecting the first electrode and the second electrode via the conductive particles. can do.

The first member to be connected and the second member to be connected are not particularly limited. Specifically, the first connection target member and the second connection target member include electronic components such as semiconductor chips, semiconductor packages, LED chips, LED packages, capacitors and diodes, as well as resin films, printed circuit boards, flexible Examples include electronic components such as circuit boards such as printed boards, flexible flat cables, rigid flexible boards, glass epoxy boards and glass boards. The first member to be connected and the second member to be connected are preferably electronic components.

The electrodes provided on the connection object members include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS electrodes, and tungsten electrodes. When the member to be connected is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. When the electrode is an aluminum electrode, it may be an electrode made of only aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of materials for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal elements include Sn, Al and Ga.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. The invention is not limited only to the following examples.

(Example 1)
(1) Production of Conductive Particles Resin particles (particle size: 20 μm) formed from a copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene were prepared. After dispersing 10 parts by weight of the base particles in 100 parts by weight of an alkaline solution containing 5% by weight of the palladium catalyst solution using an ultrasonic disperser, the solution was filtered to obtain the base particles. Next, the substrate particles were added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surfaces of the substrate particles. After thoroughly washing the surface-activated substrate particles with water, they were added to 500 parts by weight of distilled water and dispersed to obtain a dispersion. Next, 1 g of nickel particle slurry (average particle size: 100 nm) was added to the above dispersion liquid over 3 minutes to obtain a suspension containing base particles to which the core substance was attached.

A nickel plating solution (pH 8.5) containing 0.35 mol/L nickel sulfate, 1.38 mol/L dimethylamine borane, and 0.5 mol/L sodium citrate was also prepared.

While stirring the obtained suspension at 70° C., the above nickel plating solution was gradually dropped into the suspension to perform electroless nickel plating. After that, by filtering the suspension, the particles are taken out, washed with water, and dried to obtain particles in which the first conductive part (nickel-boron layer, thickness 200 nm) is formed on the surface of the substrate particles. rice field.

A suspension was obtained by adding 10 parts by weight of the particles on which the first conductive portion was formed and dispersing them in 100 parts by weight of distilled water. A reduction gold plating solution containing 0.03 mol/L of gold cyanide and 0.1 mol/L of hydroquinone as a reducing agent was also prepared. While stirring the resulting suspension at 70° C., the reduction gold plating solution was gradually dropped into the suspension to carry out reduction gold plating. After that, the particles were taken out by filtering the suspension, washed with water, and dried to obtain conductive particles. In the obtained conductive particles, the second conductive portion (gold layer, thickness 35 nm) was formed on the outer surface of the first conductive portion.

(2) Preparation of insulating particles After putting the following composition in a 2000 mL separable flask equipped with a four-necked separable cover, a stirring blade, a three-way cock, a cooling tube and a temperature probe, the composition is added to the solid content. Distilled water was added so that the content of the mixture was 10% by weight, and the mixture was stirred at 120 rpm and polymerized at 50° C. for 5 hours in a nitrogen atmosphere. The above composition contains 1080 mmol of methyl methacrylate, 10 mmol of ethylene glycol dimethacrylate (crosslinker), 0.5 mmol of 4-(methacryloyloxy)phenyldimethylsulfonium methylsulfate, and 2,2′-azobis{2-[N- (2-Carboxyethyl)amidino]propane}0.5mmol. After completion of the reaction, the mixture was lyophilized to obtain insulating particles (particle size: 540 nm) having sulfone groups derived from 4-(methacryloyloxy)phenyldimethylsulfonium methylsulfate on their surfaces.

(3) Production of conductive particles with insulating particles The insulating particles obtained above were dispersed in distilled water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of insulating particles. 10 g of the obtained conductive particles were dispersed in 500 mL of distilled water, 1 g of a 10% by weight aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 8 hours. After filtration through a 3 μm mesh filter, the particles were washed with methanol and dried to obtain conductive particles with insulating particles.

(4) Preparation of conductive material (anisotropic conductive paste) 7 parts by weight of the obtained conductive particles, 25 parts by weight of bisphenol A type phenoxy resin, 4 parts by weight of fluorene type epoxy resin, and 30 parts by weight of phenol novolac type epoxy resin Parts by weight and SI-60L (manufactured by Sanshin Chemical Industry Co., Ltd.) were blended, defoamed and stirred for 3 minutes to obtain a conductive material (anisotropic conductive paste).

(5) Fabrication of Connection Structure A transparent glass substrate was prepared on the upper surface of which an IZO electrode pattern (first electrode, electrode surface metal Vickers hardness 100 Hv) with L/S of 10 μm/10 μm was formed. In addition, a semiconductor chip having an Au electrode pattern with L/S of 10 μm/10 μm (second electrode, Vickers hardness of electrode surface metal 50 Hv) formed on the lower surface was prepared.

The obtained anisotropic conductive paste was coated on the transparent glass substrate so as to have a thickness of 30 μm to form an anisotropic conductive paste layer. Next, the semiconductor chip was laminated on the anisotropic conductive paste layer so that the electrodes faced each other. After that, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 100° C., a pressure heating head is placed on the upper surface of the semiconductor chip, and a pressure of 60 MPa is applied to the anisotropic conductive paste layer. It was cured at 100° C. to obtain a connected structure.

(Example 2)
When the insulating particles were produced, the amount of methyl methacrylate in the composition was changed from 1080 mmol to 540 mmol, and 540 mmol of glycidyl methacrylate was added to the composition. Moreover, the particle diameter of the insulating particles was changed to 750 nm when the insulating particles were produced. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(Example 3)
When the insulating particles were produced, the amount of methyl methacrylate in the composition was changed from 1080 mmol to 540 mmol, and 540 mmol of glycidyl methacrylate was added to the composition. Moreover, the particle diameter of the insulating particles was changed to 800 nm when the insulating particles were produced. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(Example 4)
When the insulating particles were produced, the amount of methyl methacrylate in the composition was changed from 1080 mmol to 540 mmol, and 540 mmol of glycidyl methacrylate was added to the composition. Moreover, the particle diameter of the insulating particles was changed to 1400 nm when the insulating particles were produced. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(Example 5)
When producing the conductive particles, the thickness of the first conductive portion (nickel-boron layer) was changed to 250 nm, and the second conductive portion (gold layer, thickness 35 nm) was not formed. Conductive particles, conductive particles with insulating particles, a conductive material and a connection structure were obtained in the same manner as in Example 3.

(Example 6)
Conductive particles, conductive particles with insulating particles, conductive material and connection structure were prepared in the same manner as in Example 3, except that the nickel particle slurry (average particle size: 100 nm) was not used in the production of the conductive particles. got a body

(Example 7)
Conductive particles, insulating A conductive particle with particles, a conductive material, and a connection structure were obtained.

(Example 8)
Conductive particles, insulating A conductive particle with particles, a conductive material, and a connection structure were obtained.

(Example 9)
Copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene instead of resin particles (particle size 20 μm) formed of copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene when producing conductive particles. Resin particles (particle size: 3 μm) formed by were used. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 3 except for the above changes.

(Example 10)
When producing the conductive particles, the thickness of the first conductive portion (nickel-boron layer) was changed to 250 nm, and the second conductive portion (gold layer, thickness 35 nm) was not formed. Further, when producing the conductive particles, instead of resin particles (particle diameter 20 μm) formed from a copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene, a copolymer of tetramethylolmethane tetraacrylate and divinylbenzene was used. Resin particles (particle size: 3 μm) formed from a polymerized resin were used. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 3 except for the above changes.

(Example 11)
Copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene instead of resin particles (particle size 20 μm) formed of copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene when producing conductive particles. Resin particles (particle size: 10 μm) formed by Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 3 except for the above changes.

(Example 12)
Copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene instead of resin particles (particle size 20 μm) formed of copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene when producing conductive particles. Resin particles (particle size: 35 μm) formed by Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 3 except for the above changes.

(Example 13)
Copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene instead of resin particles (particle size 20 μm) formed of copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene when producing conductive particles. Resin particles (particle size: 50 μm) formed by Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 3 except for the above changes.

(Example 14)
Except for changing the amount of methyl methacrylate in the composition from 1,080 mmol to 80 mmol and adding 1,000 mmol of glycidyl methacrylate to the composition in the preparation of the insulating particles, Example 3 was used. Similarly, conductive particles, conductive particles with insulating particles, a conductive material and a connection structure were obtained.

(Example 15)
Except for changing the blending amount of methyl methacrylate in the composition from 1080 mmol to 680 mmol and adding 400 mmol of glycidyl methacrylate to the composition in the preparation of the insulating particles, Example 3 was used. Similarly, conductive particles, conductive particles with insulating particles, a conductive material and a connection structure were obtained.

(Example 16)
Conductive particles and conductive particles with insulating particles were prepared in the same manner as in Example 3, except that the amount of ethylene glycol dimethacrylate in the composition was changed from 10 mmol to 15 mmol when the insulating particles were produced. Particles, conductive materials and connecting structures were obtained.

(Example 17)
Conductive particles and conductive particles with insulating particles were prepared in the same manner as in Example 3, except that the amount of ethylene glycol dimethacrylate in the composition was changed from 10 mmol to 20 mmol when the insulating particles were produced. Particles, conductive materials and connecting structures were obtained.

(Comparative example 1)
Conductive particles, conductive particles with insulating particles, conductive material and connection structure were prepared in the same manner as in Example 1, except that the particle diameter of the insulating particles was changed to 450 nm when the insulating particles were produced. Obtained.

(Comparative example 2)
Conductive particles, conductive particles with insulating particles, conductive material and connection structure were prepared in the same manner as in Example 3, except that the particle diameter of the insulating particles was changed to 450 nm when the insulating particles were produced. Obtained.

(Comparative Example 3)
Conductive particles, conductive particles with insulating particles, conductive material and connection structure were prepared in the same manner as in Example 3, except that the particle diameter of the insulating particles was changed to 360 nm when the insulating particles were produced. Obtained.

(Comparative Example 4)
When the insulating particles were produced, the amount of methyl methacrylate in the composition was changed from 1080 mmol to 540 mmol, and 540 mmol of glycidyl methacrylate was added to the composition. Moreover, the particle diameter of the insulating particles was changed to 2500 nm when the insulating particles were produced. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(Comparative Example 5)
In preparing the insulating particles, 100 mmol of dipentaerythritol hexaacrylate was added to the above composition. Moreover, the particle diameter of the insulating particles was changed to 800 nm when the insulating particles were produced. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(Comparative Example 6)
During the production of the insulating particles, 1080 mmol of 2-ethylhexyl methacrylate was added to the above composition instead of 1080 mmol of methyl methacrylate. Moreover, the particle diameter of the insulating particles was changed to 800 nm when the insulating particles were produced. Conductive particles, conductive particles with insulating particles, a conductive material, and a connection structure were obtained in the same manner as in Example 1 except for the above changes.

(evaluation)
(1) Particle Size of Insulating Particles The particle size of the obtained insulating particles was obtained by observing 50 arbitrary insulating particles with an electron microscope and calculating the average value.

(2) Storage modulus of insulating particles at 60 ° C. Using the same raw material as the obtained insulating particles (material constituting the insulating particles), measurement of length 10 mm, width 1 mm to 10 mm, thickness 15 mm to 50 mm A sample was made. The storage modulus of the measurement sample at 60 ° C. was measured using a dynamic viscoelasticity measuring device ("RSA3" manufactured by TA Instruments) at a frequency of 10 Hz, a strain of 1%, a temperature of -10 ° C. to 210 ° C., and a heating rate. Measurement was performed at 5°C/min. From the measurement results, the storage modulus at 60°C was calculated.

In addition, the measurement sample was produced as follows. A silicone rubber of 30 mm×40 mm was prepared by hollowing out the center in the shape of the size of the measurement sample (length 10 mm, width 1 mm to 10 mm, thickness 15 mm to 50 mm). The silicone rubber was placed on a 30 mm x 40 mm piece of glass. The same raw material as the insulating particles (material constituting the insulating particles) was poured into the hollowed out portion of the silicone rubber on the glass piece. The silicone rubber into which the same raw material as the insulating particles was poured was covered with a glass piece of 30 mm×40 mm and fixed with a clip to obtain a laminate. The obtained laminate was placed in an oven and reacted at 50° C. for 5 hours under a nitrogen atmosphere. After the reaction, the clip was removed and the measurement sample was taken out.

(3) Swelling Ratio of Insulating Particles Using the same raw material as the insulating particles obtained, a measurement sample of 10 mm long×5 mm wide and 0.5 mm thick was prepared. The obtained measurement sample was weighed and immersed in 100 g of toluene at 25° C. for 20 hours. After that, the measurement sample was taken out, dried at 160° C. for 30 minutes, and the weight of the measurement sample after drying was measured. The swelling ratio was calculated by the following formula (1) from the weight change of the measurement sample before and after immersion in toluene.

Swelling ratio=[Weight (g) of measurement sample after immersion in toluene/Weight (g) of measurement sample before immersion in toluene] Equation (1)

(4) Among the total number of insulating particles, the ratio X of the number of insulating particles arranged on the surface of the conductive particles so as not to contact other insulating particles
The obtained conductive particles with insulating particles were observed with a scanning electron microscope (SEM), and the number of insulating particles in 20 conductive particles with insulating particles, and the number of insulating particles in contact with other insulating particles. The number of insulating particles that do not exist was calculated. From the obtained results, the ratio X of the number of insulating particles arranged on the surface of the conductive particles, out of the total number of insulating particles, so as not to contact other insulating particles, was set to 20. It was calculated as an average value of conductive particles with insulating particles. The ratio X of the above numbers was determined according to the following criteria.

[Determination criteria for the ratio X of the number of insulating particles arranged on the surface of the conductive particles so as not to contact other insulating particles, out of the total number of insulating particles]
AA: Number ratio X is 50% or more A: Number ratio X is 30% or more and less than 50% B: Number ratio X is 10% or more and less than 30% C: Number ratio X is less than 10%

(5) Particle Size of Conductive Particles The particle sizes of the obtained conductive particles were measured using a “laser diffraction particle size distribution analyzer” manufactured by Horiba, Ltd. In addition, the particle diameter of the conductive particles was calculated by averaging 20 measurement results.

Also, the ratio of the particle size of the conductive particles to the particle size of the insulating particles was calculated from the measurement results of the particle size of the insulating particles and the particle size of the conductive particles.

(6) Continuity reliability (between upper and lower electrodes)
The connection resistance between the upper and lower electrodes of the obtained 20 connection structures was measured by the four-probe method. From the relationship of voltage=current×resistance, the connection resistance can be obtained by measuring the voltage when a constant current flows. Conductivity reliability was determined according to the following criteria.

[Continuity Reliability Judgment Criteria]
○○○: Connection resistance is 2.0 Ω or less ○○: Connection resistance is over 2.0 Ω and 5.0 Ω or less ○: Connection resistance is over 5.0 Ω and 10 Ω or less ×: Connection resistance is over 10 Ω

(7) Insulation reliability (between laterally adjacent electrodes)
In the 20 connection structures obtained in the above (6) Evaluation of conduction reliability, the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance value with a tester. Insulation reliability was evaluated according to the following criteria.

[Insulation Reliability Criteria]
○○○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 18 or more ○○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 15 or more and less than 18 ○: Resistance value 10 or more and less than 15 connection structures with a resistance value of 10 ⁸ Ω or more ×: less than 10 connection structures with a resistance value of 10 ⁸ Ω or more

The results are shown in Tables 1-3 below.

DESCRIPTION OF SYMBOLS 1... Conductive particle with an insulating particle 2... Conductive particle 3... Insulating particle 11... Base particle 12... Conductive part 21... Conductive particle with an insulating particle 22... Conductive particle 31... Conductive part 32... Core substance 33... Protrusion 41... Conductive particle with insulating particles 42... Conductive particle 51... Conductive part 52... Protrusion 81... Connection structure 82... First connection object member 82a... First electrode 83... Second connection object Member 83a... 2nd electrode 84... Connection part

Claims (8)

Conductive particles having at least a conductive portion on the surface;
A plurality of insulating particles arranged on the surface of the conductive particles,
The insulating particles have a particle diameter of 500 nm or more and 1500 nm or less,
Conductive particles with insulating particles, wherein the storage elastic modulus of the insulating particles at 60° C. is 100 MPa or more and 1000 MPa or less. 2. The conductive particles with insulating particles according to claim 1, wherein said conductive particles have protrusions on the outer surface of said conductive portion. The conductive particles with insulating particles according to claim 1 or 2, wherein the ratio of the particle size of the conductive particles to the particle size of the insulating particles is 3 or more and 100 or less. The conductive particles with insulating particles according to any one of claims 1 to 3, wherein the insulating particles have a swelling ratio of 1 or more and 2.5 or less. 5. Any one of claims 1 to 4, wherein 10% or more of the total number of said insulating particles are arranged on the surface of said conductive particles so as not to contact other said insulating particles. Conductive particles with insulating particles according to. The conductive particles with insulating particles according to any one of claims 1 to 5, wherein the conductive particles have a particle diameter of 1 µm or more and 50 µm or less. A conductive material comprising the conductive particles with insulating particles according to any one of claims 1 to 6 and a binder resin. a first connection target member having a first electrode on its surface;
a second connection target member having a second electrode on its surface;
comprising the first connection target member and a connection portion connecting the second connection target member,
The material of the connection portion is the conductive particles with insulating particles according to any one of claims 1 to 6, or a conductive material containing the conductive particles with insulating particles and a binder resin. ,
A connection structure in which the first electrode and the second electrode are electrically connected by the conductive portion in the conductive particles with insulating particles.

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